Hangman is a popular paper-and-pencil game for two people. I have frequently used it as a traiing activity by dividing the participants into pairs.
To play this game, you think of a word or a phrase and indicate the number of letters by drawing short blanks for each letter on a piece of paper. The other player tries to guess the word by calling out one letter at a time. If that letter appears in your word, you place it in the appropriate blank. (If it appears more than once, you place it in all appropriate blanks.)
The other player continues calling out new letters and you continue placing each letter in the correct blank. When the player guesses your word completely, they win.
What if the other player calls out a letter that does not appear in your word? Then you start drawing lines to progressively to build gallows (by drawing one straight line at a time) and hang a stick figure.
The game ends when the other player wins (by correctly guessing your word) or loses (by calling out several incorrect letters and getting “hanged”).
For a more engaging game, you can two players beginning with secretly selected words on a common topic, such as leadership traits. The players take turns calling out a letter and getting feedback.